Going into too much detail from this volume going forward would mean giving away some fairly crucial spoilers. Let's just say that we learn more about Rei and his twin brother, Sei in this one, and their relationship with their father in particular. Rei opens up more to Kira about his family, which is something he doesn't usually do. And they spend a special day together away from the craziness of their ordinary, everyday life. Kira and Rei begin moving closer to physical intimacy, but Kira struggles with an inner block, something I already know about, but Rei isn't sure what's causing her fears. All he knows is that he's growing more and more sexually frustrated and while Kira might be fine to never go there (or she thinks she is), Rei isn't fine with it, at all, but he doesn't know what to do.
And cue the dude who will be the villain in the next couple of volumes, and was the overarching villain throughout the entire Japanese liveaction drama series and movie.
I like this volume because it gives greater depth into Rei's character. It's still not perfect, primarily because Shiori puts in another appearance and because Rei and Kira wax very melodramatic in this one. But the entire series is a melodrama, so what in the world am I saying. I have nothing really to complain about.